There are a number of existing patents relating to the structure of tubing injector heads, such as: U.S. Pat. No. 5,553,668 (Council et al 1996); U.S. Pat. No. 6,209,634 (Avakov et al 2001); U.S. Pat. No. 6,719,043 (Austbo et al 2004). These systems use a roller chain drive system that drives a gripper chain. The roller chain passes over a linear pressure beam. The roller chain has an outer side which engages an inner side of the gripper chain.